http://hdl.handle.net/10271/1 RSSチャネルの検索 検索 http://hikumano.hama-med.ac.jp/dspace/simple-search http://hdl.handle.net/10271/1902 タイトル: Electrospray ionization tandem mass spectrometric determination of monomethylarsonic acid and dimethylarsinic acid after adduct formation with citric acid <br/> <br/>著者: Minakata, Kayoko; Ohnishi, Kazunori; Nakamura, Satoki; Suzuki, Masako; Suzuki, Osamu <br/> <br/>抄録: Inorganic arsenic species are metabolized to monomethylarsonic acid (MMA V) and dimethylarsinic acid (DMA V) and excreted into urine. A simple, rapid and sensitive method has been developed using electrospray ionization tandem mass spectrometry (ESI-MS-MS) for the simultaneous determination of MMA V and DMA V. MMA V and DMA V in a sample were allowed to react with citric acid (CiA). Adduct compounds were extracted together with isoamyl alcohol (IAA). An aliquot (1-μL) of the IAA layer was directly injected into the ESI-MS-MS instrument, and was detected within 1 min. Quantification was done using selected reaction monitoring for MMA V and DMA V as follows. [MMAH + 2CiA - 3H2O]+ → [MMAH + CiA - 2H2O]+ [DMAH + CiA + MeOH - 2H2O]+ → [DMAH + MeOH - H2O]+ Where, MMAH and DMAH denote the protonated forms of MMA V and DMA V, and MeOH denotes methanol (carrier liquid in ESI-MS-MS). This method was validated for the analysis of urine samples. The limit of detection of As was 0.3 μgL-1 for MMA V and 0.6 μgL-1 for DMA V using 10 μL of sample solution. Results were obtained in <10 min with a linear calibration range of 3-100 μgL-1. Inorganic arsenic compounds (and other organic arsenic compounds) found in urine did not interfere with the detection of MMA V and DMA V. Concentrations of MMA V and DMA V in the reference urine SRM 2670a were estimated after partial purification, and those in urine of a patient treated with As2O3 were measured after dilution. http://hdl.handle.net/10271/1900 タイトル: Simple analysis of naphthalene in human whole blood and urine by headspace capillary gas chromatography with large volume injection <br/> <br/>著者: Watanabe, Kanako; Hasegawa, Koutaro; Yamagishi, Itaru; Nozawa, Hideki; Suzuki, Osamu <br/> <br/>抄録: Naphthalene is still being sold as a moth repellant; there is a possibility that accidental ingestion of such a product by a small infant causes serious poisoning. In this communication, a very simple method for analysis of naphthalene in human whole blood and urine by headspace gas chromatography (GC) has been presented. It neither needs solid-phase microextraction nor cryogenic trapping devices, but needs only a conventional capillary GC instrument with flame ionization detection. The advantage of the method is that as large as 5 ml of headspace vapor can be injected into a GC instrument in the splitless mode for sensitive detection. After heating a diluted whole blood or urine sample containing naphthalene and 1-methylnaphthalene (internal standard, IS) in a 7.0 ml vial at 80℃ for 30 min, 5 ml of the headspace vapor was drawn with a glass syringe and injected into the gas chromatograph. Before injection, the column was set at 50℃ to trap the analytes, and then the oven temperature was programmed up to 300℃. Sharp peaks were obtained for both analyte and IS, and only a few impurity peaks, which did not interfered with the test peaks, appeared especially for whole blood samples. The detection limits (signal-to-noise ratio ≧ 3) were about 0.05 and 0.01 μg/ml for whole blood and urine, respectively. Precision and linearity were also examined to confirm the reliability. Such a simple headspace GC technique with large volume injection can be probably applied also to other low-volatile compounds in biological matrices, and will be useful in forensic toxicological analysis. http://hdl.handle.net/10271/1901 タイトル: Application of thermoresponsive HPLC to forensic toxicology: determination of barbiturates in human urine <br/> <br/>著者: Kanno, Sanae; Watanabe, Kanako; Hirano, Seishiro; Yamagishi, Itaru; Gonmori, Kunio; Minakata, Kayoko; Suzuki, Osamu <br/> <br/>抄録: A high-performance liquid chromatography (HPLC) method has been developed for the assays of five barbiturates in human urine using a new thermoresponsive polymer separation column, which is composed of N-isopropylacrylamide polymer. According to elevating the column temperature from 10 ℃ to 50 ℃, five barbiturates, such as metharbital, primidone, phenobarbital, mephobarbital and pentobarbital, became well separated by this method. Five barbiturates showed good linearity in the range of 0.2-10 mg/ml. Good accuracy, precision and recoveries for these drugs were obtained at 1 and 5 μg/ml urine. The method with the new-type column seems to have high potential to be extensively used in forensic toxicology for analysis of many drugs and poisons by HPLC and HPLC-mass spectrometry (MS) (-MS). http://hdl.handle.net/10271/1899 タイトル: Rapid screening of melamine in dried milk without destroying the samples by Raman spectroscopy <br/> <br/>著者: Okazaki, Shigetoshi; Hiramatsu, Mitsuo; Gonmori, Kunio; Suzuki, Osamu; Tu, Anthony T. <br/> <br/>抄録: Melamine is a raw ingredient for plastics, but it is frequently misused by adding it to food to give the false impression of a high protein content, since the molecule has a very high nitrogen content. Samples of dried milk obtained from 5 manufacturers containing varying levels of melamine were illuminated by a small cross-section of a laser beam and the scattered light was examined. The presence of melamine in contaminated milk could be immediately detected without any chemical or physical alteration of the milk by interpreting its Raman scattering spectra. Among its many Raman bands, the intense 676 cm-1 band was the most useful for detecting melamine; detection limit was about 1% (w/w). Because this method does not extract melamine from the dried milk sample, it reduces the risk of error that may occur during the extraction and interaction with chemical reagents. The method provides a very rapid screening test for melamine-adulterated dried milk in food chemistry and forensic toxicology.